JPS6237318B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger using heat pipes, and more particularly to a heat exchanger having a configuration in which an evaporation side heat pipe group and a condensation side heat pipe group are placed separately.

FIGS. 1 and 2 are schematic diagrams of a conventional heat exchanger of this type. In this heat exchanger, the evaporation side heat pipe group 1 and the condensation side heat pipe group 2 are arranged at different locations. Evaporation side heat pipe group 1
is mainly composed of two or more heat pipes 3 installed together, an upper header 4 that communicates the upper openings of the heat pipes 3 with each other, and a lower header 5 that communicates the lower openings of the heat pipes 3 with each other. . The condensing side heat pipe group 2 includes two or more heat pipes 6 installed side by side, and an upper header 7 that communicates the upper openings of the heat pipes 6 (however, in the heat exchanger shown in FIG. 2, the upper header 7 ), and a lower header 8 that communicates the lower openings of the heat pipes.

Before starting the heat exchanger, a condensate (not shown) of a working medium consisting of water, alcohol, ammonia, benzene, chlorofluorocarbons, high boiling point oil, liquid metal, etc. is transferred to the lower header 5 of the evaporation side heat pipe group 1. It is stored in.

When a high-temperature fluid flows around the outer periphery of the evaporation-side heat pipe group 1, the working medium starts to evaporate while taking away the heat retained in the fluid, and the vapor is sent to the condensation-side heat pipe group 2 as a vapor flow. When a low-temperature fluid flows around the outer periphery of the condensing side heat pipe group 2, the working medium vapor that has flowed into the heat pipe 6 condenses while releasing liquefaction heat. The condensed liquid of the working medium flows down the inner surface of the heat pipe 6 to the lower header 8, and then flows down to the lower header 5 of the evaporation side heat pipe group 1.
will be returned to. By repeating such an evaporation/condensation cycle of the working medium, heat is transported as latent heat of evaporation from the evaporation side to the condensation side, and heat is exchanged therebetween.

In the case of the heat exchanger shown in FIG. 1, the steam distribution pipe body 9 for sending the working medium vapor collected in the upper header 4 of the evaporation side heat pipe group 1 to the condensation side heat pipe group 2 is connected to the condensation side heat pipe It is connected to the upper header 7 of group 2. Further, a condensate distribution pipe body 10 for sending the working medium condensate collected in the lower header 8 of the condensing side heat pipe group 2 to the condensing side heat pipe group 1 is connected to the lower header 5 of the evaporating side heat pipe group 1. ing.

However, in this heat exchanger, since the working medium vapor is supplied from the upper part of the heat pipe 6 in the condensing side heat pipe group 2, the flow of the working medium vapor in the heat pipe 6 is poor. Furthermore, in the heat exchanger having this configuration, there is no accumulation of non-condensable gas that would be an obstacle to heat transport.

In the case of the heat exchanger shown in FIG.
and the condensate distribution pipe body 10 are integrated to connect the upper header 4 of the evaporation side heat pipe group 1 and the lower header 8 of the condensation side heat pipe group 2.
Therefore, while the working medium condensate generated in the condensing side heat pipe group 2 flows down to the lower header 5 through the steam distribution pipe 9 and the inner surface of the heat pipe 3, it always comes into contact with the upwardly flowing working medium vapor. in a state. Therefore, the return of the condensed liquid is poor, and a dryout phenomenon may occur in the evaporation side heat pipe group 1, and the heat held by the vapor of the working medium is taken away by the cooled condensed liquid. For these reasons, conventional heat exchangers were unable to perform efficient heat exchange and had problems with their service life.

An object of the present invention is to eliminate the drawbacks of the prior art described above and provide a highly efficient heat exchanger.

To achieve this objective, the present invention separates the vapor delivery pipe and the condensate delivery pipe, and connects the upper header of the evaporating heat pipe group and the lower header of the condensing heat pipe group in the vapor delivery pipe. The present invention is characterized in that the lower header of the condensing side heat pipe group and the lower header of the evaporating side heat pipe group are connected by a condensate distribution pipe body.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a schematic diagram of a heat exchanger according to an embodiment of the present invention. The difference between this heat exchanger and the heat exchanger shown in FIG. 1 is the installation state of the steam distribution pipe 9. That is, in the heat exchanger according to the present invention, the vapor distribution pipe body 9 extending from the upper header 4 of the evaporation side heat pipe group 1 is connected to the lower header 8 of the condensation side heat pipe group 2.

The vapor of the working medium collected in the upper header 4 of the evaporation side heat pipe group 1 is sent to the lower header 8 of the condensation side heat pipe group 2 by the vapor distribution pipe body 9. The steam enters from the lower end opening of each heat pipe 6 and is cooled and condensed while rising inside the heat pipe 6. The condensate flows down along the inner surface of the heat pipe 6, is collected in the lower header 8, and is directly sent to the lower header 5 of the evaporation side heat pipe group 1 by the condensate distribution pipe body 10.

The non-condensable gas that originally existed in the heat pipe groups 1 and 2 and the delivery pipe bodies 9 and 10, or that was generated during use, is transferred to the condensing side heat by the flow of working medium vapor. The non-condensable gas is collected in the upper header 7 of the pipe group 2 and excluded from the heat exchange system.

In the heat exchanger of the present invention, when the vapor of the working medium is sent to the heat pipe 6, there is a concern that the flow of the condensate may be obstructed. Therefore, if the structure of the lower header 8 is made as shown in FIG. 4, the above-mentioned concerns can be effectively resolved.

That is, the lower header 8 has a double tube structure including an outer tube 11 and an inner tube 12 disposed inside the outer tube 11 at a predetermined interval. Outer tube 11
The lower end opening of each heat pipe 6 is air-liquid-tightly joined to the peripheral wall of the inner tube 12, and short branch pipes 13 are erected at positions corresponding to the lower end opening of each heat pipe 6 on the peripheral wall of the inner tube 12. The tip of the branch pipe 13 is inserted into the lower end opening of each heat pipe 6. This inner tube 12 is made integrally with the steam distribution tube 9, or the tip of the steam distribution tube 9 is connected to one end of the inner tube 12 by welding or the like.

Therefore, the working medium steam 14 sent from the steam distribution pipe body 9 passes through the inner pipe 12 and enters the branch pipes 1, respectively.
The steam is fed into the center of the heat pipe 6 from the steam outlet 15 of No. 3. On the other hand, the condensate 16 of the working medium flows down along the inner surface of the heat pipe 6, passes between the heat pipe 6 and the branch pipe 13, and reaches the bottom of the outer pipe 11.

In this example, the branch pipe 13 having the steam outlet 15 is provided on the peripheral wall of the inner tube 12, but it is also possible to simply provide the steam outlet 15 on the peripheral wall of the inner tube 12, corresponding to the center of the lower end opening of the heat pipe 6. In this way, the lower header 8 is made into a double pipe structure consisting of the outer pipe 11 and the inner pipe 12, and the inner pipe 12 is formed with the steam port 15 corresponding to the lower end opening of the heat pipe 6 to be used exclusively for sending the steam 14, and one side If the outer tube 11 is used exclusively for collecting the condensed liquid 16, the supply of the steam 14 and the recovery of the condensed liquid 16 become smooth.

FIG. 5 is a diagram showing a modification of the lower header 8. In this example, the bottom of the lower header 8 is gradually inclined in one direction to form a liquid reservoir 17, and a plate-shaped vapor intrusion prevention member 18 is provided in the space above the liquid reservoir 17.
is installed. The condensate 16 generated within the heat pipe 6 flows down its inner surface and is collected in a reservoir 17, from where it is transferred to the condensate distribution pipe 10.
and is sent to the evaporation side heat pipe group 1. On the other hand, the steam 14 sent from the steam distribution pipe body 9 is sent into each heat pipe 6 through the lower header 8, but a part of the steam 14 comes into contact with the condensate 16 collected in the liquid reservoir 17. Sometimes. When the steam 14 comes into contact with the cooled condensate 16, the retained heat is taken away, so a steam intrusion prevention member 18 is provided above the liquid reservoir 17 to prevent the steam 14 from coming into contact with the collected condensate 16. .

In particular, the lower header 8 having this structure is effective when the joint with the steam distribution pipe 9 and the joint with the condensate distribution pipe 10 are close to each other.

The present invention is configured as described above, and the working medium vapor flows smoothly in the condensing side heat pipe group. Further, since the flow of the vapor of the working medium and the flow of the condensate face each other only in the condensing side heat pipe group, the obstruction of the flow of the condensate due to the vapor flow can be reduced. Furthermore, non-condensable gas can be collected in the upper header of the condensing side heat pipe group. This results in a heat exchanger that is efficient and has a long service life.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams of a conventional heat exchanger, Figure 3 is a schematic diagram of a heat exchanger according to the present invention, and Figures 4 and 5 are condensing side diagrams of a heat exchanger according to the present invention. FIG. 3 is an enlarged sectional view of a main part of the lower header of the heat pipe group. 1... Evaporation side heat pipe group, 2... Condensation side heat pipe group, 3, 6... Heat pipe, 4, 7
... Upper header, 5, 8 ... Lower header, 9
...Steam delivery pipe, 10...Condensate delivery pipe, 1
DESCRIPTION OF SYMBOLS 1... Outer pipe, 12... Inner pipe, 14... Working medium vapor, 15... Steam outlet, 16... Working medium condensate, 17... Liquid reservoir, 18... Steam intrusion prevention member.

Claims (1)

[Scope of Claims] 1. An evaporation-side heat pipe group that includes heat pipes and has an upper header and a lower header that communicate the upper and lower openings of the heat pipes, respectively, and A condensing side heat pipe group having an upper header and a lower header that communicate the upper and lower openings of the pipes, respectively, is installed separately, and the working medium vapor collected in the upper header of the evaporating side heat pipe group is transferred to the condensing side. A heat exchanger comprising a steam delivery pipe for sending the steam to the heat pipe group, and a condensate delivery pipe for sending the working medium condensate collected in the lower header of the condensing side heat pipe group to the evaporation side heat pipe group. The condensate distribution pipe connects the lower header of the condensing heat pipe group and the evaporating heat pipe group such that the delivery pipe connects the upper header of the evaporating heat pipe group and the lower header of the condensing heat pipe group. A heat exchanger characterized in that each heat exchanger is arranged so as to connect with a lower header of the heat exchanger. 2. In claim 1, the lower header of the condensing side heat pipe group includes an outer pipe having a peripheral wall joined to a lower end opening of the heat pipe, and an inner pipe disposed inside the outer pipe. It has a double-tube structure, one end of which is communicated with the steam distribution pipe body, and a steam outlet corresponding to the lower end opening of the heat pipe is formed in the peripheral wall of the inner pipe. heat exchanger. 3. Claim 1 is characterized in that a liquid reservoir for storing a working medium condensate is provided in the lower header of the condensing side heat pipe group, and a vapor intrusion prevention member is disposed above the liquid reservoir. heat exchanger.